I have the same question and yes it is shown in the manual nut it does not make sense. Step #2 says to press and hold the volume/select button, and later step #5 says to press the same button, but you are still holding it? How does that work? Something is missing in this sequence. I must not be seeing something in the pictures.
1) Select Input
2) Press and HOLD Volume/Select button
3) Press SUB button on remote
4) Release SUB button on remote
5) Press Volume/Select (BUT YOU ARE STILL HOLDING IT)
6) LED Turns Purple
7) Press SUB on remote (and release?)
I cannot make sense of the picture. Can somebody please give a written description of what to do to disable and then later enable standby mode?